1. Field of the Invention
The present invention concerns a rotor of a pressure wave machine in accordance with the preamble.
2. Discussion of Background
In pressure wave machines, when they are used as the supercharging unit for internal combustion engines, ambient air is compressed to boost air; when they are used as the high pressure compressor stage of a gas turbine, precompressed air is further compressed to produce driving gas for the high pressure turbine part. The compression of the air takes place in a rotor whose periphery has cells, which in present-day designs run parallel to the axis, in which cells the air comes into direct contact, without any solid separating element, with the exhaust gas from the engine or with driving gas branched off from the combustion chamber of the turbine group. In order to control the inlets and outlets of air and gas into or out of the cells, a casing with ports for the supply and/or removal of the two media participating in the pressure wave process is located at the two end faces of the rotor. If a cell filled with air which has to be compressed passes in front of a high pressure gas inlet, a pressure wave propagates into the cell where it compresses the air. This pressure wave reaches the end of the cell as soon as the latter passes the high pressure air outlet. At this point, the air is expelled and the cell is then completely filled with gas. On further rotation, expansion waves ensure that the gas leaves the cell again and that fresh air is induced, whereupon the compression process is repeated.
A critical circumstance, which is also decisive for the pressure wave machine process, consists in the fact that the dimensions of the cells cannot be arbitrarily increased without influencing the pressure wave machine process and that, for machines with different power, rotors with different diameters have to be provided in each case.